1. Field of the Invention
The present invention relates to an antenna device including an antenna element to be fed and to a mobile device including the antenna device.
2. Description of the Related Art
To date, a radio-communication antenna has become an indispensable part of a mobile device, such as a mobile telephone terminal, etc. In general, a part of an antenna sometimes disadvantageously protrudes from a housing of a device because it is necessary to ensure an electric characteristic (radiation characteristic) of the antenna. Also, in the case of a built-in antenna, the antenna occupies a substantial area inside a housing, and thus unfortunately the device becomes physically large in size.
In order to satisfy both necessities of the radiation characteristic and demands for design, there are requests for making an antenna section of a mobile device transparent.
Up to now, indium tin oxide (ITO) has been familiar as a transparent and conductive material. ITO is in rapidly increasing demand for a touch panel, etc.
As a transparent electrode material replacing a transparent ITO vapor-deposition electrode material used for an electromagnetic-wave shield, a liquid-crystal panel, and a solar cell, etc., a proposal has been made on a transparent electrode including a transparent supporting body and a conductive segment pattern formed thereon, and the conductive segment pattern has a thickness of 0.02 to 20 μm, and a line width of 0.5 to 100 μm (Japanese Unexamined Patent Application Publication No. 9-147639).